1. Field of the Invention
The present invention relates to a display apparatus and a control method thereof.
2. Description of the Related Art
A high definition medical monitor (a display apparatus for displaying medical images) typically displays medical images output from an external apparatus such as a PC (personal computer). It is predicted, however, that in the future highly sophisticated medical monitors on which medical images can be displayed simply by a monitor alone will be developed. It is also predicted that a portable monitor (display apparatus) will be developed as this type of medical monitor. By using this type of medical monitor, it will be possible to perform a normal reading operation using a sophisticated PC (software stored on the PC) and the monitor, and to provide explanations and the like to a patient using the monitor alone (by displaying medical images simply using the monitor). It is also predicted that this type of medical monitor will be connected to a network. Accordingly, it is predicted that a medical monitor which obtains images from the network and displays the obtained images will be developed.
In the case of a monitor such as that described above, an appearance (a display characteristic) of a displayed image must be matched to a target value. However, an image input from a PC (an external input image hereafter) may vary according to a characteristic of a graphic board provided in the PC and processing performed in the PC (image processing performed in the PC, for example). In other words, an identical image may exhibit a different display characteristic as an external input image and an image displayed by the monitor alone (a single unit display image). To solve this problem, it may be necessary to perform both calibration (link calibration hereafter) of the display characteristic of the external input image and calibration (single unit calibration hereafter) of the display characteristic of the single unit display image as display characteristic calibration.
Related art pertaining to calibration is disclosed in Japanese Patent Application Publication No. 2002-057911 and Japanese Patent Application Publication No. 2005-208548, for example.
More specifically, Japanese Patent Application Publication No. 2002-057911 discloses a technique for correcting a result of a soft calibration on the basis of a result of a device calibration. The soft calibration is performed on the basis of data obtained by reading a printing result of a printer using a scanner. The device calibration is performed automatically in the printer on the basis of a potential of a latent image formed on a photosensitive drum and a density of a toner image.
Japanese Patent Application Publication No. 2005-208548 discloses a technique in which a photometry unit provided to face a liquid crystal display unit performs photometry, whereupon calibration is performed on the basis of a difference value between a result of the photometry and a predetermined ideal value.